Malware is any software used to disrupt computer operations, gather sensitive information, or gain access to private assets residing in computer systems. This can lead to the malware creator or other unauthorized parties gaining access to the computer system and private information stored on the computer system being compromised. Malware includes computer viruses, worms, trojan horses, spyware, adware, key loggers, and other malicious programs. These programs can appear in the form of computerized code, scripts, and other software.
Polymorphic Attacks
Metamorphic and polymorphic malware are two categories of malicious software programs (malware) that have the ability to change their form (morph) as they propagate. Metamorphic malware is rewritten with each iteration so that each succeeding version of the code is different from the preceding one.
Polymorphic malware is harmful, destructive or intrusive computer software such as a virus, worm, Trojan or spyware that constantly changes (“morphs”), making it difficult to detect with anti-malware programs. Evolution of the malicious code can occur in a variety of ways such as filename changes, compression, encryption with variable keys, and string changes, etc.
Although the appearance of the code in polymorphic malware varies with each “mutation,” the essential function usually remains the same. For example, a spyware program intended to act as a keylogger will continue to perform that function even though its signature changes. If the malicious program is discovered by an anti-malware vendor and its signature is added to a downloadable database, the anti-malware program will fail to detect the rogue code after the signature has changed, just as if a new virus, worm, Trojan or spyware program has emerged. In this way, malware creators gain an advantage over countermeasure developers